1. Field of the Invention
The present invention relates to a sliding door (or more appropriately a rolling door or roll-up door) for opening and closing off door and gate openings, with the door including a hanging portion that is made of flexible material, is in a sheet-like form, and is guided along its sides in a frame.
2. Description of the Prior Art
Roll-up doors of the aforementioned general type are used, on the one hand, when little heat and noise are to be allowed through, and, on the other hand, when a transparent hanging portion is desired. In contrast to conventional sliding doors having interengaging profiled sections, sliding doors of the aforementioned general type allow no greater amount of heat and noise to pass through at the connection locations, and can be made of entirely transparent synthetic materials. However, such roll-up doors have the drawback that they are less wind stable and not as strong as conventional roll-up doors that are made of profiled sections. As a result, there is a greater danger that a break in could occur. Furthermore, the synthetic materials that are used can be rolled only to a limited extent, since at low temperatures they become stiff, and at high temperatures they tend to jam in the lateral guides. Finally, at low temperatures cold flow of the synthetic material is also possible, resulting in stretching of the hanging portion of the roll-up door.
An object of the present invention therefore is to provide an improved roll-up door that is provided with a hanging portion in sheet-like form, with such a hanging portion allowing little heat and noise to pass through, it being entirely or partially transparent if desired, and having a sufficient wind stability and strength, so that it is also suitable for closing off large building openings.